Aluminum wire has been utilized for many years in such applications as overhead electricity transmission lines due to its desirable combination of relatively high conductivity and low weight. Since the most desirable attribute of such wire is the conductivity, the most popular form of aluminum for this purpose has been that alloy formerly known as EC aluminum and now known by its Aluminum Association Registration No. 1350. This particular aluminum alloy contains small amounts of silicon and iron in a high purity aluminum base to provide a wire of high conductivity but with higher strength than ultra-pure aluminum.
Unfortunately, since this particular aluminum alloy itself requires the use of a high purity aluminum as the base material for the alloy, products produced from this metal have tended to increase in cost so as to lower the benefit/cost ratio of aluminum over other materials.
Various other aluminum alloys utilizing additions, such as iron, silicon and copper have been formulated as replacement materials for Alloy 1350. Many of these alloys suffer from the disadvantage of having a lower conductivity than Alloy 1350, even though the mechanical properties of these alloys may be higher than those exhibited by Alloy 1350. For example, British Pat. No. 1,260,307 discloses an alloy system containing copper, iron and what the patent deems "rare earth metals" in an aluminum base as exhibiting increased tensile strength over presumably more pure forms of aluminum. Russian Author's Certificate No. 456,845 discloses that such elements as gadolinium, cerium, dysprosium, yttrium and lanthanum may be added to aluminum alloys containing specific proportions of iron, silicon, copper, zinc and boron. The rare earth metals are apparently added to the aluminum alloy base to improve both the mechanical properties and the electrical conductivity of the alloy. Unfortunately, both the British patent and the Russian Author's Certificate both require the use of fairly high purity grades of aluminum as the base material for the respective alloy systems.
Therefore, it is a principal object of the present invention to provide an alloy which exhibits higher electrical conductivity than commercially utilized aluminum.
It is a further object of the present invention to provide an alloy which presents equivalent conductivity to commercial aluminum alloys while utilizing lower purity grades of aluminum as the base material therein, such as commercial purity aluminum.
It is another object of the present invention to provide an alloy as aforesaid which exhibits high electrical conductivity properties while utilizing grades of aluminum in which some normal impurity levels of certain elements are enhanced for strength properties.
It is another object of the present invention to provide an alloy as aforesaid which improves the conductivity of conductor grade aluminum alloys in the cold worked, partially annealed or fully annealed condition.
Further objects and advantages of the present invention will become apparent from a consideration of the following specification.